Precision mask for deposition and a method for manufacturing the same, an electroluminescence display and a method for manufacturing the same, and electronic equipment

ABSTRACT

A precision mask for deposition is provided that includes a first brace having a plurlaity of sections placed in parallel to each other at given intervals. The first brace forms portions that define a plurality of first openings. The precision mask for deposition also includes at least one second brace that is placed on the first brace so as to intersect with the first brace. The second brace forms portions that define a plurality of second openings. The second brace is joined to the first brace at a point where the second brace intersects with the first brace.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a precision mask for depositionthat is mainly used to form a hole transport layer, an emitting layer,and the like of an organic electroluminescence (EL) display, and amethod for manufacturing the same. The invention also relates to theorganic EL display, a method for manufacturing the same, and electronicequipment having the organic EL display.

[0003] 2. Related Art

[0004] A conventional mask for deposition may be formed by wet-etching asingle crystal silicon wafer of surface orientation (100) with potassiumhydroxide or the like so as to reduce the thickness of the center of thewafer, and then by dry-etching the wafer to form an opening fordeposition corresponding to each pixel of the organic EL display (seeJapanese Unexamined Patent Application Publication No. 2001-185350, forexample). The mask for deposition corresponds to the precision mask fordeposition according to the invention.

[0005] A conventional mask for evaporation may be formed by wet-etchinga single crystal silicon wafer of surface orientation (100) withpotassium hydroxide or the like so as to reduce the thickness of part ofthe wafer, and by further wet-etching the wafer with potassium hydroxideor the like to form an evaporated pattern (an opening) (see JapaneseUnexamined Patent Application Publication No. 4-236758, for example).The mask for evaporation corresponds to the precision mask fordeposition according to the invention.

[0006] A conventional precision mask for deposition having a singlecrystal silicon wafer that is used for an organic EL display may includea plurality of elongated openings that are several dozen micrometerswide aligned as shown in FIG. 10. The openings make it possible to formpixels that are arranged lengthwise and each emit either red, green, orblue light.

[0007] The conventional mask for deposition having an opening fordeposition corresponding to each pixel of the organic EL display (seeJapanese Unexamined Patent Application Publication No. 2001-185350, forexample) involves the following problem. It is necessary to align themask for deposition with a glass substrate to which an emitting layer isevaporated within a tolerance of +/− five (5) micrometers bothlengthwise and crosswise in a vacuum evaporation room. This hindersproductivity.

[0008] The conventional mask for evaporation that is formed bywet-etching a single crystal silicon wafer of surface orientation (100)to form an opening (see Japanese Unexamined Patent ApplicationPublication No. 4-236758, for example) also involves the followingproblem. If a plurality of elongated openings that are several dozenmicrometers wide is aligned as shown in FIG. 10, part of the siliconwafer that is between two openings is too weak to withstand treatment.Thus, an evaporated wafer is not accurately patterned.

[0009] In consideration of these problems, the invention aims to providea precision mask for deposition that is easily aligned with a glasssubstrate in evaporating an emitting layer and the like of an organic ELdisplay, and is strong enough to form an accurate evaporated pattern.The invention also aims to provide a method for easily and accuratelymanufacturing such a precision mask for deposition, an organic ELdisplay and a method for manufacturing the same, and electronicequipment including an organic EL display.

SUMMARY

[0010] A precision mask for deposition according to the inventionincludes a first brace including sections (e.g., ribs) placed parallelto each other at given intervals. The first brace forms portions thatdefine a plurality of first openings. The precision mask for depositionalso includes a second brace that is placed on the first brace so as tointersect with the first brace. The second brace forms portions thatdefine a plurality of second openings. The second brace is joined to thefirst brace at a point where the second brace intersects with the firstbrace.

[0011] According to the invention, the second brace, which defines thesecond openings, serves as reinforcement for the first brace, whichdefines the first openings. The first openings are several dozenmicrometers wide and several centimeters long, which are elongated inshape. Since the second brace is joined to the first brace and serves asreinforcement, the first brace does not bend. As a result, an accurateevaporated pattern can be provided. In addition, since the firstopenings are elongated in shape, the precision mask for deposition iseasily aligned with the glass substrate when evaporating the emittinglayer etc. as described in greater detail below.

[0012] The precision mask for deposition according to the invention alsoincludes a mask substrate. The first brace and the second brace areformed to be joined to the mask substrate.

[0013] Since the first brace and the second brace are formed to bejoined to the mask substrate, the precision mask for depositionaccording to the invention provides high accuracy and rigidity.

[0014] Also as regards the precision mask for deposition according tothe invention, the mask substrate is made of single crystal silicon.

[0015] With the mask substrate that is made of single crystal silicon,the precision mask for deposition according to the invention provideshigh accuracy and rigidity. Moreover, the precision mask for depositionis easily manufactured by wet etching.

[0016] Also as regards the precision mask for deposition according tothe invention having the mask substrate that is made of single crystalsilicon, at least one of the side surfaces of the first brace and thesecond brace is of surface orientation (111).

[0017] Since at least one of the side surfaces of the first brace andthe second brace is of surface orientation (111), the precision mask fordeposition according to the invention is easily manufactured byanisotropic-etching the mask substrate that is made of single crystalsilicon by potassium hydroxide or the like, when forming the firstopenings and the second openings.

[0018] Also as regards the precision mask for deposition according tothe invention having the mask substrate that is made of single crystalsilicon, the mask substrate is integrally made of single crystal siliconof surface orientation (110). At the same time, the side surfaces of thefirst brace are perpendicular (111) to surface orientation (110) of themask substrate, and the side surfaces of the second brace, whichintersects with the first brace, are also perpendicular (111) to surfaceorientation (111) of the mask substrate.

[0019] According to the invention, the second brace, which defines thesecond openings of the mask substrate, serves as reinforcement for thefirst brace, which defines the first openings of the mask substrate.Since the second brace is joined to the first brace and serves asreinforcement, the first brace does not bend. As a result, an accurateevaporated pattern can be provided. Since both of the side surfaces ofthe first brace and the second brace are of surface orientation (111),the precision mask for deposition is easily manufactured by wet-etchinga silicon wafer by potassium hydroxide or the like, when forming thefirst openings and the second openings.

[0020] Also as regards the precision mask for deposition according tothe invention, oxygen concentration of the mask substrate that is madeof a single crystal silicon wafer is 1.7*10¹⁸ atm/cm³ or below.

[0021] The invention provides a precision mask for deposition thatprovides higher accuracy by using a single crystal silicon wafer whoseoxygen concentration is low, which can avoid developing a crystal defectwhen the mask substrate reaches a high temperature in manufacturing theprecision mask for deposition.

[0022] A method for manufacturing the precision mask for depositionaccording to the invention includes the following steps: forming anetching protective film on the mask substrate that is made of singlecrystal silicon; patterning configurations corresponding to theplurality of first openings, which is defined by the first brace on theback of the mask substrate, on the etching protective film; andpatterning configurations corresponding to the plurality of secondopenings, which is defined by the second brace on the surface of themask substrate, on the etching protective film. The method also includesthe steps of removing the etching protective film in parts that arepatterned and forming the first openings and the second openings byetching.

[0023] According to the invention, the etching protective film is formedon both the surface and the back of a single crystal silicon wafer. Thesingle crystal silicon wafer is then patterned by photolithography orthe like and removed in parts that are patterned, which is to be theopenings by anisotropic etching. With the method including these steps,a precision mask for deposition that can form an accurate evaporatedpattern is easily and accurately manufactured.

[0024] Also as regards the method for manufacturing the precision maskfor deposition according to the invention, the step of forming theetching protective film on the mask substrate that is made of singlecrystal silicon also includes the following steps: heating the masksubstrate up to 500° C. or higher; cooling the mask substrate; and ifthe temperature of the mask substrate is from 500 to 800° C., coolingthe mask substrate at an average cooling rate of at least 3° C. perminute.

[0025] If the temperature of the mask substrate is from 500 to 800° C.,it is possible to quickly pass through this temperature range in which acrystal defect is most likely to develop by cooling the mask substrateat an average cooling rate of at least 3° C. per minute makes. Thus theprecision mask for deposition according to the invention provides higheraccuracy.

[0026] Also as regards the method for manufacturing the precision maskfor deposition according to the invention, the step of forming theetching protective film on the mask substrate that is made of singlecrystal silicon also includes the following steps: forming the etchingprotective film by thermal oxidation; cooling the mask substrate; and ifthe temperature of the mask substrate is from 500 to 800° C., coolingthe mask substrate at an average cooling rate of at least 3° C. perminute.

[0027] If the temperature of the mask substrate is from 500 to 800° C.,it is possible to quickly pass through this temperature range in which acrystal defect is most likely to develop by cooling the mask substrateat an average cooling rate of at least 3° C. per minute makes. Thus theprecision mask for deposition according to the invention provides higheraccuracy.

[0028] An EL display according to the invention includes the precisionmask for deposition mentioned above.

[0029] Since the EL display according to the invention is manufacturedwith the precision mask for deposition, which provides high accuracy andis easily aligned with the glass substrate when evaporating the emittinglayer etc. as described above, the EL display offers high quality withan accurate evaporated pattern.

[0030] A method for manufacturing the EL display according to theinvention includes the step of placing the precision mask for depositionmentioned above at a predetermined position on the glass substrate so asto form an EL layer.

[0031] Since the EL display according to the invention is manufacturedwith the precision mask for deposition, which provides high accuracy andis easily aligned with the glass substrate when evaporating the emittinglayer etc. as described above, the EL display offers high quality withan accurate evaporated pattern.

[0032] Furthermore, the method for manufacturing the EL display issimple, which can reduce cost.

[0033] Electronic equipment having the EL display according to theinvention includes an EL layer that is manufactured with the precisionmask for deposition mentioned above.

[0034] The electronic equipment having the EL display according to theinvention includes the EL display, which offers high quality with anaccurate evaporated pattern. Furthermore, since the method formanufacturing the EL display is simple, cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035]FIG. 1 is a diagram schematically showing a precision mask fordeposition according to a first embodiment of the invention.

[0036]FIG. 2 is a cross-section view of an electrode part of an organicEL display according to the invention.

[0037]FIGS. 3A-3D are diagrams showing a method for manufacturing aprecision mask for deposition according to the invention.

[0038]FIG. 4 is a chart showing temperature changes by thermal oxidationshown in FIG. 3A.

[0039]FIG. 5 is a drawing showing a pattern on the surface of the masksubstrate.

[0040]FIG. 6 is a drawing showing a pattern on the back of the masksubstrate.

[0041]FIG. 7 is a comparison chart of electrode configurations for anorganic EL display.

[0042]FIG. 8 is a drawing showing the spatial relationship of the glasssubstrate and the precision mask for deposition when using evaporation.

[0043]FIGS. 9A and 9B are diagrams showing electronic equipmentaccording to a fifth embodiment of the invention.

[0044]FIG. 10 is a drawing showing a conventional precision mask fordeposition.

DETAILED DESCRIPTION

[0045] First Embodiment

[0046]FIG. 1 is a diagram schematically showing a precision mask fordeposition according to a first embodiment of the invention. The mask iscut along the A-A line in FIG. 1, and portions of the mask not shown inthis diagram are formed in the same pattern. A mask substrate 1 isprovided by cutting a single crystal silicon wafer into a rectangle.Facing the back of the mask substrate 1, a first brace 3 is provided. Inthis diagram the first brace 3 includes a plurality of braces that areplaced in parallel to each other at given intervals. The intervals are aplurality of first openings 2. Facing the surface of the mask substrate1, a second brace 5 is provided. In this diagram the second brace 5includes a plurality of braces that form a plurality of second openings4. The first brace 3 and the second brace 5 are formed to be joined tothe mask substrate 1, which is made of single crystal silicon. A methodfor manufacturing them is described below in a third embodiment. At apoint where the first brace 3 intersects with the second brace 5, theupper surface of the first brace 3 is joined to the lower surface of thesecond brace 5. When evaporating an organic EL material, the first brace3 is in contact with the evaporated material.

[0047]FIG. 1 schematically shows the precision mask for deposition. Ingeneral, the width “d” of the first openings 2 is from severalmicrometers to several dozen micrometers. The first brace 3 is abouttwice as wide as the first openings 2. The length of the first openings2 is, in general, from several centimeters to several dozen centimeters.Thus the first openings 2 are elongated in shape.

[0048] The precision mask for deposition according to the firstembodiment shown in FIG. 1 is formed by cutting the mask substrate 1 outof a single crystal silicon wafer of surface orientation (110). The sidesurfaces of the first brace 3 are perpendicular (111) to the surfaceorientation (110) of the mask substrate. The side surfaces of the secondbrace 5 intersect with the side surfaces of the first brace 3, and arealso perpendicular (111) to the surface orientation of the masksubstrate. Here, the side surfaces of the braces face neither thesurface and the back of the mask substrate 1, nor the first and secondopenings. The precision mask for deposition is provided by, for example,cutting a single crystal silicon wafer of surface orientation (110) intoa rectangle, which is to be the mask substrate 1. The first openings 2and the second openings 4 is easily formed by anisotropic etching withpotassium hydroxide or the like. A method for manufacturing theprecision mask for deposition according to the invention is describedbelow in greater detail in a second embodiment.

[0049] It should be noted that although the side surfaces of the firstbrace 3 and the second brace 5 are perpendicular to the surface of themask substrate 1 in the first embodiment, it is not always necessary toform the side surfaces of the braces perpendicular to the surface of themask substrate. For example, if the first brace 3 is formed so as tohave a trapezoidal cross-section, the first openings 2 have an invertedtrapezoidal cross-section. This makes it possible to evaporate amaterial with a wide angle.

[0050] Furthermore, the first brace 3 may be made of a differentmaterial from that of the second brace 5.

[0051]FIG. 2 is a cross-section view of an electrode part of an organicEL display that is an example of an EL display manufactured with theprecision mask for deposition according to the first embodiment of theinvention. The diagram shows that a glass substrate 6 is provided at thebottom. On the substrate, a TFT wiring layer 7, a planarizing insulatingfilm 8, and an ITO layer 9 are deposited in this order. ITO stands forindium thin oxide that serves as an anode to apply an electric currentto the pixels. Then a silicon oxide layer 10 is deposited on a part thatemits no light around each pixel. Subsequently, a hole transport layer11, an emitting layer 12, and an electron injection layer 13, all ofwhich form an EL layer and are made of an organic EL material, aredeposited by, for example, vacuum evaporation. On top of them, an ITOlayer 14 that serves as a cathode and a transparent sealant film 15 aredeposited. The precision mask for deposition shown in FIG. 1 is mainlyused as a mask for evaporating the hole transport layer 11, the emittinglayer 12, and the electron injection layer 13. In addition, the mask canbe used as a mask for sputtering when forming the ITO layer 9 bysputtering. The EL layer may include a hole injection layer and the likeif any, as well as the hole transport layer 11, the emitting layer 12,and the electron injection layer 13.

[0052] The precision mask for deposition (the mask substrate 1)according to the first embodiment includes the second brace 5 that isjoined to the first brace 3. Therefore, the mask is strong enough towithstand treatment and forms an accurate evaporated pattern. Also asregards the precision mask for deposition according to the firstembodiment, as shown in a fourth embodiment described later in detail,the emitting layer 12 etc. are deposited while the first openings 2,which are elongated in shape, are aligned with a portion on the glasssubstrate 6 where pixels are formed. This makes it easy to align themask substrate 1 with the glass substrate 6, which can improveproduction efficiency.

[0053] Also according to the first embodiment, the side surfaces of thefirst brace 3 and the second brace 5 are perpendicular (111) to the masksubstrate 1. This makes it easy to form the precision mask fordeposition by anisotropic etching with potassium hydroxide or the like.In addition, since the side surfaces of the first brace 3 areperpendicular to the mask substrate 1, the first openings 2 can beformed precisely.

[0054] Second Embodiment

[0055]FIG. 3 shows cross-section views of the mask substrate 1illustrating a method for manufacturing the precision mask fordeposition according to the first embodiment. First, the mask substrate1 is provided by cutting a single crystal silicon wafer of surfaceorientation (110) into a rectangle. After cleaning the mask substrate 1,an etching protective film 17 that is made of silicon oxide (SiO₂) isformed by thermal oxidation so as to surround the mask substrate 1 (seeFIG. 3(a)). The etching protective film 17 may be obtained by forming asilicon nitride film by chemical vapor deposition (CVD) or forming agold-chrome alloy film by sputtering instead of by forming a siliconoxide film by thermal oxidation.

[0056] According to the second embodiment, single crystal silicon whoseoxygen concentration is 1.7*10¹⁸ atm/cm³ or below is used for the masksubstrate 1. If the temperature of the mask substrate 1 is from 500 to800° C. after forming the etching protective film 17 by thermaloxidation, the mask substrate 1 is cooled at an average cooling rate ofat least 3° C. per minute.

[0057]FIG. 4 is a chart showing an example of temperature changes informing the etching protective film 17 by thermal oxidation as shown inFIG. 3A. When the temperature reaches 800° C., the temperature isincreased up to 1100° C. by supplying oxygen to a thermal oxidationroom. When the temperature reaches 1100° C., steam is supplied to thethermal oxidation room in order to accelerate thermal oxidation. Whenthermal oxidation is completed after keeping the temperature of 1100° C.for a while, nitrogen is supplied in order to stabilize the etchingprotective film 17. Then, the temperature is lowered from 1100° C.

[0058] If the temperature of the mask substrate 1 is from 500 to 800°C., the mask substrate 1 is cooled at an average cooling rate of atleast 3° C. per minute. This is because the possibility of developing acrystal defect of single crystal silicon is highest in this temperaturerange. If the mask substrate 1 has a crystal defect, openings may not beaccurately formed by anisotropic etching. Developing such a crystaldefect can be avoided by passing through this temperature range quickly.

[0059] The mask substrate also reaches a temperature of 500° C. orhigher when forming the etching protective film 17 of silicon nitride byC VD or the etching protective film 17 of gold-chrome alloy bysputtering instead of thermal oxidation. Also in these cases, if thetemperature of the mask substrate is from 500 to 800° C., developing acrystal defect can be avoided by cooling the mask substrate at anaverage cooling rate of at least 3° C. per minute.

[0060] Furthermore, by using single crystal silicon whose oxygenconcentration is 1.7*10¹⁸ atm/cm³ or below for the mask substrate 1,developing a crystal defect caused by a higher-temperature process canbe avoided. It is known that a crystal defect rarely grows under theabove-mentioned conditions, that is, applying the average cooling rateof at least 3° C. per minute if the temperature is from 500 to 800° C.and using single crystal silicon whose oxygen concentration is 1.7*10¹⁸atm/cm³ or below for the mask substrate 1.

[0061] Next, configurations corresponding to the first openings 2 thatare defined by the first brace 3 are patterned on the back of the masksubstrate 1 where the etching protective film 17 is formed. Also,configurations corresponding to the second openings 4 that are definedby the second brace 5 are patterned on the surface of the masksubstrate. The configurations are patterned by photolithography onportions other than the openings. FIG. 5 shows a pattern on the surfaceof the mask substrate 1, while FIG. 6 shows a pattern on the back of themask substrate 1. Photolithography is performed in the grayed areas inFIGS. 5 and 6. Here, the arrows “J” and “K” in FIGS. 5 and 6 are in thedirection of (111). Then the mask substrate 1 on which theconfigurations are patterned is etched by a solution of hydrofluoricacid and ammonium fluoride so as to remove the etching protective filmin parts to be the openings (see FIG. 3B). Here, a part to be analignment mark 20 that is necessary when setting a position ofevaporating the emitting layer 12 etc. of the organic EL display that ismentioned in the first embodiment is also etched.

[0062] The mask substrate 1 that is etched as shown in FIG. 3B is thenanisotropic-etched with a potassium hydroxide solution so as to form thefirst openings 2 and the second openings 4 (see FIG. 3C). By wet etchingwith potassium hydroxide, part of the mask substrate that is not coveredby silicon oxide is etched accurately with the side surfaces of surfaceorientation (111). When the organic EL display includes a semiconductor,organic alkaline solutions such as a tetramethylammonium hydroxidesolution are preferably used for etching, instead of the potassiumhydroxide solution. This is because the semiconductor may becontaminated by potassium. Also in this case, anisotropic etching can beperformed as is the case with potassium hydroxide.

[0063] Finally, the etching protective film 17 that remains on the masksubstrate 1 shown in FIG. 3C is removed by a buffer hydrogen fluoridesolution or the like. As a result, the precision mask for deposition isformed (see FIG. 3D).

[0064] By performing anisotropic etching after forming the etchingprotection film, the method for manufacturing a precision mask fordeposition according to the second embodiment makes it possible toeasily and accurately manufacture a precision mask for deposition thatis strong enough to form an accurate evaporated pattern as shown inFIG. 1. Moreover, by cooling the mask substrate 1 at an average coolingrate of 3° C. per minute if the temperature is from 500 to 800° C. so asto quickly pass through this temperature range in which a crystal defectis likely to develop, and by using single crystal silicon whose oxygenconcentration is 1.7*10¹⁸ atm/cm³ or below for the mask substrate 1, themethod makes it possible to avoid developing a crystal defect andthereby to accurately perform anisotropic etching.

[0065] Third Embodiment

[0066] The electrode part of an organic EL display whose EL layer ismanufactured with the precision mask for deposition according to thefirst embodiment of the invention has a cross section as shown in FIG.2. An electrode configuration as viewed from the surface side of an ELdisplay according to a third embodiment is called vertical stripes.Three major electrode configurations for an organic EL display aredescribed below.

[0067]FIG. 7 is a comparison chart of the electrode configurations foran organic EL display in terms of the difficulty of thin-film transistor(TFT) wiring, image display quality, and character display quality. TFTwiring means general wiring for driving an organic EL display. Itcontrols switching on and off of each pixel. Electrode configurationshave an important influence on display quality, in particular, asregards a full-color low-molecular organic EL display. As shown in FIG.7, a configuration called delta configuration has the disadvantages ofcomplicated TFT wiring and low character display quality. Aconfiguration called square configuration also has the disadvantages ofrather complicated TFT wiring and high cost. In the configuration calledvertical stripes, pixels whose width is 20 and length is 60 micrometers,for example, are arranged. An organic EL display of vertical stripesrequires simple TFT wiring and low cost, while it provides high imageand character display quality.

[0068] Since the precision mask for deposition shown in FIG. 1 includesthe first openings 2 that are elongated in shape, it is suitable formanufacturing the organic EL display of vertical stripes.

[0069] Since the EL display according to the third embodiment ismanufactured with the precision mask for deposition according to thefirst embodiment shown in FIG. 1, which is sufficiently strong, thedisplay provides high precision with accurate pixel patterns. Inaddition, since the display adopts the vertical-stripe pixelconfiguration, it requires simple TFT wiring and low costs, while itprovides high image and character display quality.

[0070] Fourth Embodiment

[0071]FIG. 8 shows the spatial relationship of the glass substrate 6 andthe precision mask for deposition (the mask substrate 1) whenvacuum-evaporating the EL layer to the organic EL display shown in FIG.2 in manufacturing the organic EL display. The organic EL display shownin FIG. 8 adopts the vertical-stripe pixel configuration. The TFT wiringlayer 7, the planarizing insulating film 8, the ITO layer 9, and thesilicon oxide layer 10 are deposited on the glass substrate 6. The masksubstrate 1 (not shown in the diagram) is provided in a manner that itsback (the side on which the first openings 2 are formed) is in contactwith the glass substrate 6. As shown in FIG. 8, the first openings 2 arealigned with vertical lines of pixels. In addition, an evaporationsource is on the side of the mask substrate 1. The first openings 2 aredesigned so as to provide an opening every three vertical pixel linesand evaporate pixels that emit the same color at a time. In other words,red pixels 21R, green pixels 21G, and blue pixels 21B are each arrangedlengthwise. Pixels of a desired color are evaporated only by moving themask substrate 1 to the line of pixels of the color and aligning themask substrate 1 with the glass substrate 6.

[0072] Above the mask substrate 6, the silicon oxide layer 10, which isan insulator, is deposited on a part that emits no light around eachpixel as shown in FIG. 2. Thus, even if the EL layer is formed over thefirst openings 2, pixels are separated one another. Whenvacuum-evaporating the emitting layer 12 etc., it is thereforesufficient to pay attention only to lateral alignment accuracy and notto longitudinal alignment accuracy when aligning the mask substrate 1with the glass substrate 6. Since the mask substrate 1 is aligned withthe glass substrate 6 in a vacuum evaporation room, achieving highlongitudinal and alignment accuracies requires time and money, andreduces production efficiency as a result.

[0073] However, using the precision mask for deposition (the masksubstrate 1) shown in FIG. 1 makes it easy to align the mask substrate 1with the glass substrate 6, which improves production efficiency. Inaddition, since the first openings 2 are elongated in shape, the mask issuitable for manufacturing the organic EL display of vertical-stripepixel configuration.

[0074] In order to reduce the need for high longitudinal alignmentaccuracy as mentioned above, one option is to use such a mask forevaporation as one shown in FIG. 10. The problem here is that bracesbetween elongated openings are several dozen micrometers wide ingeneral, which are too weak to withstand treatment. This means it isdifficult to make an accurate evaporated pattern. The precision mask fordeposition shown in FIG. 1, however, includes at least one of the secondbrace 5, which is joined to the first brace 3. Thus, the first brace 3does not easily bend.

[0075] Here, the emitting layer 12 etc. may not be evaporated evenlybecause of the second brace 5. To solve this problem, thicknessdistribution is evenly balanced within a pixel by rotating the glasssubstrate 6 and the mask substrate 1 together in a vacuum evaporationroom and moving an evaporation source as required.

[0076] Furthermore, as regards the method for manufacturing an ELdisplay according to the fourth embodiment, the emitting layer 12 etc.are deposited while the first openings 2, which are elongated in shape,are aligned with a portion on the glass substrate 6 where pixels areformed. This makes it easy to align the mask substrate 1 with the glasssubstrate 6, which can improve production efficiency. Moreover, sincethe precision mask for deposition (the mask substrate 1) according tothe first embodiment includes the second brace 5, the mask is strongenough to withstand treatment and forms an accurate evaporated pattern.

[0077] Fifth Embodiment

[0078]FIG. 9 is a diagram showing electronic equipment according to afifth embodiment of the invention. FIG. 9A shows an example of the ELdisplay according to the invention used as a display panel of a cellularphone. FIG. 9B shows an example of the EL display according to theinvention used as a display panel of a digital panel. Other examples inwhich the EL display according to the invention can be used as a displayinclude game machines and computers.

[0079] The entire disclosure of Japanese Patent Application No.2003-011451 filed Jan. 20, 2003 is incorporated by reference.

What is claimed is:
 1. A precision mask for deposition, comprising: afirst brace including a plurlaity of sections parallel to each other atgiven intervals, the first brace forming portions that define aplurality of first openings; a second brace on the first brace andintersecting with the first brace; the second brace forming portionsthat define. a plurality of second openings; and the second brace beingjoined to the first brace at a point where the second brace intersectsthe first brace.
 2. The precision mask for deposition according to claim1, further comprising: a mask substrate; wherein the first brace and thesecond brace are joined to the mask substrate.
 3. The precision mask fordeposition according to claim 2, wherein the mask substrate comprisessingle crystal silicon.
 4. The precision mask for deposition accordingto claim 3, wherein at least one of side surfaces of the first brace andside surfaces of the second brace is of surface orientation (111). 5.The precision mask for deposition according to claim 3, wherein the masksubstrate comprises single crystal silicon of surface orientation (110);side surfaces of the first brace are perpendicular (111) to surfaceorientation (110) of the mask substrate; and side surfaces of the secondbrace are perpendicular (111) to surface orientation (110) of the masksubstrate.
 6. The precision mask for deposition according to claim 3,wherein the mask substrate comprises single crystal silicon having anoxygen concentration of 1.7*10¹⁸ atm/cm³ or below.
 7. A method formanufacturing the precision mask for deposition according to claim 1,the method comprising the steps of: forming an etching protective filmon the mask substrate that is made of single crystal silicon; patterningconfigurations corresponding to the plurality of first openings, definedby the first brace on the back of the mask substrate, on the etchingprotective film; patterning configurations corresponding to theplurality of second openings, defined by the second brace on the surfaceof the mask substrate, on the etching protective film; removing theetching protective film in parts that are patterned; and forming thefirst openings and the second openings by etching.
 8. The method formanufacturing the precision mask for deposition according to claim 7,the step of forming the etching protective film on the mask substratethat is made of single crystal silicon further comprising the steps of:heating the mask substrate up to 500° C. or higher; cooling the masksubstrate; and cooling the mask substrate at an average cooling rate ofat least 3° C. per minute in a temperature range from 500 to 800° C. 9.The method for manufacturing the precision mask for deposition accordingto claim 8, the step of forming the etching protective film on the masksubstrate that is made of single crystal silicon further comprising thestep of: forming the etching protective film by thermal oxidation. 10.An electroluminescence display comprising: an electroluminescence layerthat is formed with the precision mask for deposition according toclaim
 1. 11. A method for manufacturing an electroluminescence display,the method comprising the step of: placing the precision mask fordeposition according to claim 1 at a predetermined position on the glasssubstrate so as to form the electroluminescence layer.
 12. Electronicequipment, comprising: the electroluminescence display according toclaim
 10. 13. A precision mask for deposition, comprising: a first braceincluding a plurality of first spaced apart parallel ribs defining aplurality of first openings; and a second brace including a plurality ofsecond spaced apart parallel ribs defining a plurality of secondopenings, the first brace being joined to the second brace where thefirst ribs intersect the second ribs.